Sailboat

ABSTRACT

Sailboat comprises propulsion unit which carries all the requisites for propulsion of the sailboat by wind force, and a carrying unit for the carrying of goods and passengers. The units are connected together in a manner such that the carrying unit is not subjected to the heeling angular displacement which results from propulsion by sail.

United States Patent Ross Apr. 30, 1974 [54] SAILBOAT FOREIGN PATENTS oRAPPLICATIONS 1 lnvemofl Abrilham ROSS, 1400 Tahiti 1,005,089 12/1951France .1 114/91 Marina Del Rey, Calif. 93933 [22] Filed: Deg 26, 1972Primary Examiher-Trygve M. Blix App]. N0.: 318,015

US. Cl 114/39, 114/91, 114/123 Int. Cl B63b 35/00, B63h 9/00 Field ofSearch 114/39, 91, 123

References Cited UNITED STATES PATENTS 12/1925 Thorburn .1 114/91 3/1928Ostcn 114/123 Attorney, Agent, or Firm-Allan M. Shapiro [57] ABSTRACTSailboat comprises propulsion unit which carries all the requisites forpropulsion of the sailboat by wind force, and a carrying unit for thecarrying of goods and passengers. The units are connected together in amanner such that the carrying unit is not subjected to the heelingangular displacement'which results from propulsion by sail.

3 Claims, 3 Drawing Figures SAILBOAT BACKGROUND OF THE INVENTION 1.Field of the Invention This invention is directed to a sailboat, andparticularly to a sailboat wherein the unit arranged for the carrying ofgoods and passengers is not subjected to heeling angles.

2. Description of the Prior Art The sailboat is an ancient developmenthaving a long lineage. It has, since earliest times, evolved as a vesselfor the carrying of goods and passengers to which is directly attachedthe requisites for propelling this vessel by wind force. Theserequisites include a sail, and the wind force upon the sail tends totilt the vessel hull. Therefore, hulls for sailing vessels have beendesigned to produce a maximized righting moment. The righting moment isthe force which tends to return the hull toward the upright position,when it is tilted away from the upright position by wind or wave force.The maximization of righting force is necessary in a sailboat to preventthe wind force from laying the sailboat over. Another effect of windforce is the sideways drift of the sailing vessel. To overcome thissideways drift, hull design, centerboards, and keels have been employedto maximize sideward resistance. With the use of the keel, the keel canbe weighted to produce additional righting moment.

With this structure, when wind force acts laterally upon the sail, theentire structure heels. This heeling is uncomfortable to passengers andis sometimes detrimental to goods carried in the hull of the vessel. Asa result of this, attempts have been made to permit the mast to heelfarther than the hull so that the hull heels at a lesser angle than themast. These attempts have not fully recognized the problem or itssolution. The righting moment produced by heeling must be equal to theheeling force caused by the wind on the sail. Thus, when the hullsupplies the entire righting moment, it cannot ride level, when there isa lateral wind force, because there is no righting moment with levelriding. Thus, some heeling of the hull has been required in priorstructures.

SUMMARY OF THE INVENTION In order to aid in the understanding of thisinvention, it can be stated in essentially summary form that it isdirected to a sailboat. The sailboat comprises apropulsion unit, thepropulsion unit having at least a mast for carrying a sail forpropulsion, a flotation structure for providing a righting moment, and akeel for providing lateral resistance and additional righting moment.Pivotally mounted on the propulsion unit on a fore-and aft pivot axis isa carrying unit for carrying goods and/or passengers. The carrying unitprovides some flotation, at least to support part of the load of thecarrying unit and its contents.

Accordingly, it is an object of this invention to provide a sailboat inwhich the passengers are separated from the heeling resulting from windforce on the sail. It is another object to separate the propulsionstructure of the sailboat from the part that carries passengers. It isyet another object to attach all of the elements necessary for sailboatpropulsion to a propulsion unit and pivotally attach thereto a carryingunit for supporting and carrying the useful load of the sailboat. It isyet an other object to provide a propulsion unit which is pivotallyattached to a carrying unit upon a longitudinal axis, with first andsecond floats on opposite sides of the axis and a weighted keel belowthe axis.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. The presentinvention, both as to its organization and manner of operation, togetherwith further objects and advantages thereof, may best be understood byreference to the following description, taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of thesailboat of this invention.

FIG. 2 is an enlarged side elevational view thereof, with the mastbroken away.

FIG. 3 is a stern view of the sailboat, as shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The sailboat of this inventionis generally indicated at 10 in FIGS. 1, 2 and 3. Sailboat 10 iscomprised of two units. Carrying unit 12 is in suitable form forcarrying cargo and passengers and for providing at least some of thebuoyancy necessary for supporting that load. It preferably resembles thetraditional hull, as shown. It has a fore and aft axis defined by shaftsl4 and 16. Car rying unit 12 is described in more detail below.

Propulsion unit 18 has three principal members. Mast 20 extends upwardand supports one or more conventional sails. The rig of the sails can beof any of the well-known rigs, and, for the mast illustrated, a Marconirig would be expected. However, the particular rig of the sails isunimportant to the principles of this invention and, thus, the mast 20can be used to support sails in any conventional rig. For ease andclarity of illustration, the sails are not shown in the drawings. Mast20 is supported in an upright position by means of stays 22, 24 and 26,which are secured to the mast at their upper ends and are preferablysecured to other portions of the propulsion unit at their lower ends.

The propulsion unit 18 also includes floats 28 and 30. Furthermore,propulsion unit 18 includes keel 32. The three assemblies of propulsionunit 18, i.e., mast 20 with its sails, floats 28 and 30, and keel 32,are rigidly secured together by connector 34. Connector 34 is in theshape of a hoop or ring which carries a mast step 36 at its upper pointinto which mast 20 is seated. Connector 34 passes through and isconnected to both of floats 28 and 30 so that the floats provide abuoyant support for the propulsion unit. Finally, the lower portion ofconnector 34 passes beneath carrying unit 12 and carries keel 32thereon.

In sailing, the force of the-wind upon the sail produces a force on mast20, including a forward component for propulsion of the sailboat andusually includes a lateral component which produces heeling. Tworighting moments are provided to counteract the wind force. First ofall, keel 32 is a weighted keel, and heeling of the sailboat moves thekeel to a position where it is not directly underneath the longitudinalcenter line or axis, but is to one side thereof. The gravity componentwhich urges the weighted keel 32 to a point where it is below thelongitudinal center line is a righting moment which tends to force themast 20 to the upright position. Another righting moment for thepropulsion unit is received from the differential flotation forces offloats 28 and 30, as the propulsion unit heels. For example, if the windis coming from the position of the viewer in FIG. 1, float 28 will beforced farther down into the water, and float 30 will rise somewhatfarther out of the water as the mast 20 heels to the right, as seen inFIG. 3. The normal at-rest water line is indicated by water level 38 inFIGS. 2 and 3.

As the sailboat moves forward and the leeward float is thrust down (inthis case, float 28) and the windward float is lifted, in addition tothe differential buoyancy, a differential in forward drag is found. Thefloat farther into the water has more drag than the one lifted. Thistends to cause the sailboat to fall off the wind, or to self-steer in adirection which is not as close into the wind. To overcome this, rudders40 and 42 are respectively secured to the rear of floats 28 and 30.These rudders preferably are fixed and shaped so that the area of therudder immersed in the water increases faster than the immersion of thefloat. This is accomplished by having the rudder longer from front toback at the top than it is at the bottom. Furthermore, the rotaryeffectiveness is further increased with immersion by having greatercamber or twist at the top than at the bottom, with progressiveincreasing twist from bottom to top.

When the sailboat is viewed from the top, in the level condition of thepropulsion unit with both floats equally immersed, there is a balance ofmoments around a vertical axis due to float drag. With heeling, the skinfriction drag on the leeward float increases so that there is a momenttending to turn the sailboat downwind. However, due to these fixedrudders, there is a balancing steering moment due to immersion of thefixed rudders which causes the drag moment around the vertical axis tobe neutralized.

As is conventional in sailboat practice, all underwater parts of thepropulsion unit are designed to minimize forward drag and maximizelateral drag. For in creased stability, connector 44 can interconnectthe floats on keel 32 toward the rear thereof. The flotation provided bythe normal immersion of the floats in the water is about equal to theweight of the propulsion unit.

Forward arm 46 extends forward from keel 32 and extends upward to carrybearing 48 thereon. Bearing 48 is on the longitudinal axis of heeling ofthe propulsion unit 18 and receives shaft 14. Additionally, aft arm 50extends rearwardly and carries bearing 52 thereon. Bearing 52 is also onthe longitudinal axis of the propulsion unit and receives shaft 16.

Carrying unit 12 is of such height and of such shape that it ispartially immersed in the water to cause water displacement. It isillustrated as being in conventional boat hull form and has an open topproviding cockpit 54. Cockpit 54 has seats 56 and 58 therein forpassengers. The sailboat is illustrated as being a fairly small boat forthe carrying of a few passengers or a small cargo with one sailor.However, the size of the sailboat in the drawings is merelyillustrative, and principles of this invention can be employed with asailing vessel of fairly large dimensions. Carrying unit 12 is of suchdimensions that it has a righting moment of its own, when it may tilt inthe water. Rotation about this righting moment is substantially on thefore and aft axis defined by shafts l4 and 16. Thus, the lateral forceof wind or waves against carrying unit 12 and the unbalanced load withinthe carrying unit will not cause tipover of the carrying unit, as longas they stay within the tolerable limits.

Rudder 60 is mounted at the rear of the sailboat and is selectivelymovable on a vertical axis, as by manual control of tiller 62. Rudder 60can be mounted either upon the propulsion unit or the carrying unit but,since the carrying unit rides substantially upright in the water and thesailor will be riding therein, it is more convenient to pivotally mountrudder 60 on the carrying unit, As illustrated, this is accomplished byhaving it pivotally mounted on the rear of shaft 16. With this mountingof the rudder 60 as substantially upright in the water, it isindependent of heeling of the propulsion unit.

From the described structure, it is clear that, when underway, lateralforce upon the sail on mast 20 causes a heeling force, while the floatsand keel cause a righting moment. This causes the propulsion unit toheel on a longitudinal axis, and this axis is preferably a substantiallylongitudinal axis through bearings 48 and 52. Since carrying unit 12 isalso pivotally mounted upon its longitudinal axis of rolling, it isindependent of heeling of the propulsion unit. While carrying unit 12 issubjected to local forces, such as wave forces, such are minor comparedto the heeling due to sail forces and, thus, the carrying unit 12 ridesupright. in order to minimize rotary interconnection of the propulsionunit and carrying unit along their common axis, carrying unit 12 hasflotation substantially equal to its own weight and the average load itis expected to carry. This minimizes bearing loads to achieve the mostsatisfactory interrelationship.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from thisinvention in its broader aspects and, therefore, the aim in the appendedclaims is to cover all such changes and modifications as fall within thetrue spirit and scope of this invention.

What is claimed is:

l. A sailboat comprising:

a propulsion unit, said propulsion unit having 'a longitudinal axis,said propulsion unit having a mast for carrying a sail, a keel, andflotation means for providing flotation for said propulsion unit, aconnector substantially rigidly connecting together said mast, saidkeel, and said flotation means;

said flotation means of said propulsion unit comprising first and secondfloats, said first and second floats being laterally separated onopposite sides of said longitudinal axis of said propulsion unit andeach of said floats being connected to said connector;

each of said floats having a fixed rudder secured on the after endthereof, each of said fixed rudders being directed rearwardly and towardsaid axis in a direction to cause a steering torque to overcomeincreased drag of one of said floats due to heeling and increasedimmersion in the water, each of said fixed rudders having compoundcurvature to provide increased torque with increased immersion so that,when lateral force acts on said mast, said propulsion unit heels withrotation being substantially on its longitudinal axis and a rightingmoment is produced-by increased immersion of one of said floats to limitheeling and a corrective steering torque is produced by increasedimmersion of said fixed rudder on said one of said floats; carryingunit, said carrying unit being boat-hullshaped to displace water whensaid sailboat is in water to produce flotation for said carrying unit,said carrying unit being positioned between said floats and over saidkeel, said carrying unit having the longitudinal axis, amanually-directable rudder movably mounted on said carrying unit forapplying torque to said sailboat for controlling the course direction ofsaid sailboat; and pivot means on the longitudinal axis on saidpropulsion unit and on the longitudinal axis on said carrying unit forpivotally interconnecting said propulsion unit and said carrying unit sothat said propulsion unit can heel in response to sail forces and saidcarrying unit is substantially isolated from rotation of said propulsionunit about said axis.

2. The sailboat of claim 1 wherein:

a forward arm forms a part of said propulsion unit and extends forwardof said carrying unit to the axis thereof, and an aft arm forms part ofsaid propulsion unit and extends to the rear of said carrying unit atthe axis thereof, there being bearings and shafts on said arms and onsaid carrying unit for rotary inter-engagement therebetween on saidlongitudinal axis.

3. The sailboat of claim 2 wherein:

said arms extend from said keel forward and aft to said axis.

1. A sailboat comprising: a propulsion unit, said propulsion unit havinga longitudinal axis, said propulsion unit having a mast for carrying asail, a keel, and flotation means for providing flotation for saidpropulsion unit, a connector substantially rigidly connecting togethersaid mast, said keel, and said flotation means; said flotation means ofsaid propulsion unit comprising first and second floats, said first andsecond floats being laterally separated on opposite sides of saidlongitudinal axis of said propulsion unit and each of said floats beingconnected to said connector; each of said floats having a fixed ruddersecured on the after end thereof, each of said fixed rudders beingdirected rearwardly and toward said axis in a direction to cause asteering torque to overcome increased drag of one of said floats due toheeling and increased immersion in the water, each of said fixed ruddershaving compound curvature to provide increased torque with increasedimmersion so that, when lateral force acts on said mast, said propulsionunit heels with rotation being substantially on its longitudinal axisand a righting moment is produced by increased immersion of one of saidfloats to limit heeling and a corrective steering torque is produced byincreased immersion of said fixed rudder on said one of said floats; acarrying unit, said carrying unit being boat-hull-shaped to displacewater when said sailboat is in water to produce flotation for saidcarrying unit, said carrying unit being positioned between said floatsand over said keel, said carrying unit having the longitudinal axis, amanuallydirectable rudder movably mounted on said carrying unit forapplying torque to said sailboat for controlling the course direction ofsaid sailboat; and pivot means on the longitudinal axis on saidpropulsion unit and on the longitudinal axis on said carrying unit forpivotally interconnecting said propulsion unit and said carrying unit sothat said propulsion unit can heel in response to sail forces and saidcarrying unit is substantially isolated from rotation of said propulsionunit about said axis.
 2. The sailboat of claim 1 wherein: a forward armforms a part of said propulsion unit and extends forward of saidcarrying unit to the axis thereof, and an aft arm forms part of saidpropulsion unit and extends to the rear of said carrying unit at theaxis thereof, there being bearings and shafts on said arms and on saidcarrying unit for rotary inter-engagement therebetween on saidlongitudinal axis.
 3. The sailboat of claim 2 wherein: said arms extendfrom said keel forward and aft to said axis.